SwagBucks pays for more than just surveys. Members can also get rewards for shopping, trying offers, watching videos and more. Survey quantity is less than some of the others but they make up for it with more options.
Referral Program: Earn $3 and 10% for life from active referrals.
Index: SurveySavvy | ClixSense | InstaGC | SwagBucks | PrizeRebel | YouGov | PaidViewpoint | BrandedSurveys | MyPoints | Springboard America